One example of a conventionally known film having desirable gas barrier properties, toughness, pinhole resistance, etc., usable as a packaging film is that obtained by depositing an inorganic substance on the surface of a polyester-based film or polyamide-based film, to form a deposition layer.
However, because a polyester-based film is hard, it does not have sufficient bending resistance. Further, pinholes are formed in the deposition layer provided on the polyester-based film due to bending, adversely affecting the barrier properties.
In contrast, a polyamide-based film has a high pinhole resistance. However, it is subject to dimensional change caused by moisture absorption. This generates cracking in the deposition film provided on the polyamide-based film due to the dimensional change of the polyamide-based film, adversely affecting the barrier properties.
As described above, there is currently no multilayer stretched film with barrier property that is totally free from dimensional change due to moisture absorption and/or deterioration of barrier properties caused by bending, and the like.